Cards for Sample Storage and Delivery Comprising Sintered Porous Plastic

ABSTRACT

This application discloses cards comprising sintered porous plastic which may be employed in liquid sample collection, storage, transport and/or delivery to an analytical device. Sintered porous plastic materials provide a unique porous structure, an inert substrate, precise liquid holding capability, are quick drying, and easy to cut and handle.

FIELD OF THE INVENTION

The present invention provides cards comprising sintered porous plasticwhich may be employed in liquid sample collection, storage, transportand/or delivery to an analytical device.

BACKGROUND

Sample cards found in the prior art are made of cellulose and are usedto collect blood samples. Such cards include the Whatman FTA cards knownto one of ordinary skill in the art as DMPK-A, DMPK-B and DMPK-C cards.Some of these cards may provide problems with increased background noiseor interference in an analytical method such as mass spectroscopy due tointerfering substances in the card. These cards also display long dryingtimes after application of a liquid sample. Cellulose based products incertain cases may not be compatible with analytes of interest formeasurement. Accordingly, there is a need for new media that canovercome the shortfalls of current sample card media and providereliable, fast and broad range of compatibilities for sample collection,storage and subsequent analysis.

SUMMARY

This application solves the problems inherent in prior art cards anddiscloses cards comprising sintered porous plastic which may be employedin liquid sample collection, storage, transport and/or delivery to ananalytical device. This application also discloses methods of making andusing these cards.

These cards comprise sintered porous plastic which is used to receive,transport or store the liquid sample. These regions of sintered porousplastic to which a sample is applied are called sample receiving spots.Optionally, the sample receiving spots may be linked through channels tosample storage spots. These channels and sample storage spots are alsocomprised of sintered porous plastic.

Sample receiving spots are located or configured in a card. Whenpresent, the channels and sample storage spots are also located orconfigured in the card.

The regions of the card other than the sample receiving spot, thechannel and the sample storage spot comprise materials which may be thesame as or different from the sintered porous plastic. These regions maybe sintered porous plastic, paper, cardboard, glass, and transparent ornon-transparent solid non-porous plastic.

Sintered porous plastic sample receiving spots comprise a sinteredporous matrix made by fusing individual plastic particles together in asintering process to form the sintered porous matrix. These sinteredporous plastic sample receiving spots configured in a card provide aunique porous structure, an inert substrate, precise liquid holdingcapability, dry quickly and are easy to cut and handle.

The card contains one or more liquid sample receiving spots for receiptof a liquid sample. In one embodiment, a portion of the spot may belater removed for subsequent processing and analysis of the samplecontained in the spot. In another embodiment, the entire samplereceiving spot may be later removed from the card for subsequentprocessing and analysis of the sample contained in the spot. Theperimeter of the sample receiving spot may be configured for easyremoval from the card.

The sintered porous matrix in the liquid sample receiving spot, in thechannel and in the sample storage spot each optionally comprisesfunctional additives. Functional additives include, but not limited tothe following: polyelectrolytes, C-18, C-8 or C-4 modified silica,silica gel, ion exchange material, controlled porous glass (CPG), solidphase extraction (SPE) media, cell lysis reagents, protein denaturingadditives, chemicals that denature or de-activate proteins and/or lysecells, anti-oxidants, chemicals that preserve the analyte to be measuredin the sample, enzyme inhibitors, antimicrobials, color changeindicators, chelating agents, surfactants, DNA stabilizing agents, aweak acid, such as Tris(hydroxymethyl)aminomethane (TRIS), a chaotropicagent, an anti-coagulant, or a combination thereof.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1. Schematic representation of a sample card showing three samplespot receiving regions A, B, and C comprised of sintered porous plastic,surrounded by a region of the card that does not receive a sample.

FIG. 2. Schematic representation of a sample card showing three samplespot receiving regions A, B, and C comprised of sintered porous plastic,surrounded by a region of the card that does not receive a sample. Theperimeter of each sample spot comprises weak edges for easy detachmentof the sample receiving spot from the card.

FIG. 3. Schematic representation of a sample card showing three samplespot receiving regions A, B, and C comprised of sintered porous plastic,surrounded by a region of the card that does not receive a sample. Eachsample spot receiving region comprises a shallow region as the thicknessof the card in the sample spot receiving region is less than thesurrounding region of the card that does not receive a sample.

FIG. 4. Schematic representation of a sample card showing three samplespot receiving regions A, B, and C comprised of sintered porous plastic,surrounded by a region of the card that does not receive a sample. Eachsample spot receiving region is hydrophilic while the surrounding regionof the card that does not receive a sample is hydrophobic.

FIG. 5. Schematic representation of a hydrophilic-hydrophobic samplecard. The center of the card contains a hydrophilic sample receivingspot connected by hydrophilic channels to hydrophilic sample storagespots all comprised of sintered porous plastic. The area of the cardsurrounding the hydrophilic sample receiving spot, the hydrophilicchannels, and the hydrophilic sample storage spots is hydrophobic.

FIG. 6. Schematic representation of a sharp point of sintered porousplastic containing a sample. Following application of voltage, chargedparticles containing the sample are released from the sharp point andintroduced into a mass spectrometer for analysis of selected analytes.

FIG. 7. Schematic representation of a sample card showing three samplespot receiving regions A, B, and C comprised of sintered porous plastic,surrounded by a region of the card comprised of paper, cardboard, glassor solid non-porous plastic that does not receive a sample. Each samplespot receiving region comprises a shallow region as the thickness of thecard in the sample spot receiving region is less than the surroundingregion of the card that does not receive a sample.

FIG. 8. Standard curve of UV Absorption for serial dilution of caffeinein water.

DETAILED DESCRIPTION

This application discloses cards comprising sintered porous plasticwhich may be employed in liquid sample collection, storage, transportand/or delivery to an analytical device. This application also disclosesmethods of making and using these cards.

These cards comprise sintered porous plastic which is used to receive,transport or store the sample. These regions of sintered porous plasticto which a sample is applied are called sample receiving spots.Optionally, the sample receiving spots may be linked through channels tosample storage spots. These channels and sample storage spots are alsocomprised of sintered porous plastic.

Sample receiving spots are located or configured in a card. Whenpresent, the channels and sample storage spots are also located orconfigured in the card.

The regions of the card other than the sample receiving spot, thechannel and the sample storage spot comprise materials which may be thesame as or different from the sintered porous plastic. These regions maybe sintered porous plastic, paper, cardboard, glass, and transparent ornon-transparent solid non-porous plastic.

Sintered porous plastic sample receiving spots comprise a sinteredporous matrix made by fusing individual plastic particles together in asintering process to form the sintered porous matrix. These sinteredporous plastic sample receiving spots configured in a card provide aunique porous structure, an inert substrate, precise liquid holdingcapability, dry quickly and are easy to cut and handle.

The card contains one or more sample receiving spots for receipt of aliquid sample. In one embodiment, a portion of the spot may be laterremoved for subsequent processing and analysis of the sample containedin the spot. In another embodiment, the entire sample receiving spot maybe later removed from the card for subsequent processing and analysis ofthe sample contained in the spot. The perimeter of the sample receivingspot may be configured for easy removal from the card.

Each of the sintered porous matrix in the sample receiving spot, in thechannel and in the sample storage spot optionally comprises functionaladditives. Functional additives include, but not limited to thefollowing: polyelectrolytes, C-18, C-8 or C-4 modified silica, silicagel, ion exchange material, controlled porous glass (CPG), solid phaseextraction (SPE) media, cell lysis reagents, protein denaturingadditives, chemicals that denature or de-activate proteins and/or lysecells, anti-oxidants, chemicals that preserve the analyte to be measuredin the sample, enzyme inhibitors, antimicrobials, color changeindicators, chelating agents, surfactants, DNA stabilizing agents, aweak acid, such as Tris(hydroxymethyl)aminomethane (TRIS), a chaotropicagent, an anti-coagulant, or a combination thereof.

Cards Composition and Properties of Cards

Cards are comprised of one or more sample receiving spots comprising asintered porous plastic matrix and regions that do not receive a sample.The cards may be any shape including circular, oblong, polygonal,triangular, trapezoidal, rectangular or square.

Sample Receiving Spots

The sintered porous matrix in the sample receiving spot, the channel orin the sample storage spot may be made from a variety of plastics suchas polyethylene. Polyethylenes (PE) which may be employed include butare not limited to high density polyethylene (HDPE), low densitypolyethylene (LDPE), or ultra high molecular weight polyethylene(UHMWPE), or a blend thereof. The sintered porous matrix may also bemade from polypropylene (PP), polyvinylidene fluoride (PVDF),polystyrene, polyamides, polyacrylates, polyacrylic nitrile (PAN),ethylene-vinyl acetate (EVA), polyesters, polycarbonates, orpolytetrafluoroethylene (PTFE), or a blend thereof. In one embodimentthe plastic is HDPE. In other embodiment the plastic is UHMWPE, PP,polyamides, or polyacrylic nitrile or a blend thereof. The sinteredporous matrix may also be made from a blend of any of the plasticsdisclosed in this paragraph. In other embodiments when PP and PE arecombined, PP may be present in a range of from about 100% to about 0%and PE may be present in a range of from about 0 to about 100% (100% to0%:0% to 100% wt:wt %). When PE is combined with other polymers, the PEis present in at least about 50% (wt %).

In addition to plastic, the sintered porous matrix may also comprisehydrophilic polymers, such as celluloses, polyvinyl alcohol (PVA),polyethylene glycol (PEG) or polyvinylpyrrolidone (PVP).

The sintered porous matrix has a porosity of from about 20% to about80%, from about 25% to about 70%, from about 30% to about 60%, or fromabout 30% to about 50%. The sintered porous matrix has a pore size offrom about 1 μm to about 200 μm, from about 10 μm to about 100 μm, orfrom about 20 μm to about 60 μm. The sample receiving spots can have athickness of from about 100 microns (μm) to about 5 mm, or from about200 μm to about 3 mm, or from about 0.5 mm to about 2 mm.

Cards can contain one or more sample receiving spots. The number ofsample receiving spots per card and their diameters and thicknesses areselected based on a variety of factors such as the volume capacity of anindividual spot, the suspected analyte concentration within the sampleapplied to the sample receiving spot and the assay sensitivity, and thesample volume to be applied to an individual spot. The sample receivingspot may be any shape including circular, oblong, polygonal, triangular,trapezoidal, rectangular or square.

A sample receiving spot may be hydrophobic or hydrophilic, and thisproperty is chosen depending on the sample to be applied to the samplereceiving spot. In one embodiment, the sample receiving spots arehydrophilic so that hydrophilic samples may be absorbed into the card.Hydrophilic sample receiving spots are preferred for use with bloodsamples. Hydrophobic sample receiving spots may be desirable if thesample contains surfactant or has a surface tension of the liquid sampleless than about 40 dynes/cm.

The amount of absorbed sample is controlled by the cross sectional area,thickness and pore volume of the sample receiving spot in the card. Inone embodiment, the sample is absorbed into the sample receiving spot bycapillary force.

The sample capacity of a sample receiving spot on a card may be fromabout 0.1 μl to about 500 μl, from about 1 μl to about 250 μl, fromabout 2 μl to about 225 μl, from about 3 μl to about 200 μl, from about5 μl to about 150 μl, from about 10 μl to about 100 μl, from about 5 μlto about 50 μl, from about 10 μl to about 40 μl, or from about 10 μl toabout 30 μl. The pore volume of a sample receiving spot on a card may begreater than about 1 μl or less than about 1000 μl, or any value betweenabout 1 μl and about 1000 μl, or from about 0.1 μl to about 500 μl, fromabout 1 μl to about 250 μl, from about 2 μl to about 225 μl, from about3 μl to about 200 μl, from about 5 μl to about 150 μl, from about 10 μlto about 100 μl, from about 5 μl to about 50 μl, from about 10 μl toabout 40 μl, or from about 10 μl to about 30 μl.

Regions of the Card that do not Receive Sample

The regions of the card that do not receive sample may be made fromplastic, paper, cardboard, glass or other materials

When the regions of the card that do not receive sample are made fromplastic, they may be porous or non-porous in different embodiments. Avariety of plastics may be used, such as polyethylene. Polyethylenes(PE) which may be employed include but are not limited to high densitypolyethylene (HDPE), low density polyethylene (LDPE), or ultra highmolecular weight polyethylene (UHMWPE), or a blend thereof. Otherplastics which may be used include polypropylene (PP), polyvinylidenefluoride (PVDF), polystyrene, polyamides, polyacrylates, polyacrylicnitrile (PAN), ethylene-vinyl acetate (EVA), polyesters, polycarbonates,or polytetrafluoroethylene (PTFE), or a blend thereof. In one embodimentthe plastic is HDPE. In other embodiment the plastic is UHMWPE, PP,polyamides, or polyacrylic nitrile or a blend thereof. A blend of any ofthe plastics disclosed in this paragraph may also be employed. In otherembodiments when PP and PE are combined, PP may be present in a range offrom about 100% to about 0% and PE may be present in a range of fromabout 0 to about 100% (100% to 0%:0% to 100% wt:wt %). When PE iscombined with other polymers, the PE is present in at least about 50%(wt %).

When these regions of the card that do not receive sample are comprisedof sintered porous plastic, the porosity is from about 20% to about 80%,from about 25% to about 70%, from about 30% to about 60%, or from about30% to about 50%. The pore size is of from about 1 μm to about 200 μm,from about 10 μm to about 100 μm, or from about 20 μm to about 60 μm.These regions of the card that do not receive sample can have athickness of from about 100 μm to about 5 mm, or from about 200 μm toabout 3 mm, or from about 0.5 mm to about 2 mm.

These regions of the card that do not receive sample may be hydrophobicor hydrophilic.

Functional Additives

Sample receiving spots comprising a sintered porous plastic matrix aswell as the regions of the card that do not receive a sample may containfunctional additives. Functional additives include but are not limitedto the following: polyelectrolytes, C-18, C-8 or C-4 modified silica,silica gel, ion exchange material, controlled porous glass (CPG), solidphase extraction (SPE) media, cell lysis reagents, protein denaturingadditives, chemicals that denature or de-activate proteins and/or lysecells, anti-oxidants, chemicals that preserve the analyte to be measuredin the sample, enzyme inhibitors, antimicrobials, and color changeindicators, etc. Functional additives are generally located in thesample receiving spot. Functional additives are added to the samplereceiving spots during the sintering process or after the sinteringprocess using solution treatment, depending on the sensitivity andstability of the functional additive to sintering conditions, as knownto one of ordinary skill in the art.

Functional additives also include but are not limited to chelatingagents, such as ethylene diaminetetraacetic acid (EDTA), surfactants,such as anionic surfactant, cationic surfactant or non-ionic surfactant,DNA stabilizing agents, such as uric acid or urate salt, or a weak acid,such as Tris(hydroxymethyl)aminomethane (TRIS). Functional additivesalso include but are not limited to a chaotropic agent, such as urea,thiourea, guanidinium chloride, or lithium perchlorate. Cards may alsocontain an anti-coagulant, such as heparin, citrate and/or chelatingagents. A surfactant can be an anionic surfactant, for example sodiumdodecylsulfate (SDS), sodium dodecyl sulfate (SDS), sodium dodecylbenzenesulfonate, sodium lauryl sarcosinate, sodium di-bis-ethyl-hexylsulfosuccinate, sodium lauryl sulfoacetate or sodiumN-methyl-N-oleoyltaurate, a cationic surfactant, such ascetyltrimethylammonium bromide (CTAB) or lauryl dimethyl benzyl-ammoniumchloride, a non-ionic surfactant, such as nonylphenoxypolyethoxylethanol (NP-40), Tween-20, Triton-100 or azwitterionic surfactant, such as3-[(3-Cholamidopropyl)dimethylammonio]-1-propanesulfonate.Fluorosurfactants may also be used, such as Zonyl® fluorosurfactant fromDuPont. Other surfactants may be employed as known to one of ordinaryskill in the art.

Sample cards, including sample receiving spots as well as other regionsof the card, may also be coated with layers of polyelectrolytes, such aspolyethyleneimine which may be applied in solution form. Polyelectrolytecoatings may optionally be combined with surfactants and/or ananticoagulant such as heparin.

The sintered porous plastic matrix in the sample receiving spot, thechannel or the sample storage spot may contain color change indicatorsthat dissolve upon contact with liquid and indicate the extent of sampleapplication. In one embodiment, the sample receiving spot changes colorupon contact with a liquid sample. Such color change indicators aredisclosed in US 2008/0199363. In one embodiment, the sample receivingspot changes from white to another color provided by the dye thedissolves upon contact with liquid, indicating the extent of sampleapplication. In another embodiment, the sample receiving spot may becolored and a dye dissolves upon contact with liquid to modify or reducethe coloration, indicating the extent of sample application. These colorchange indicators are particles that are located in the sintered porousplastic matrix. These particles of color change indicators are added tothe particles of plastic and mixed before sintering to form the sinteredporous plastic matrix in the area of the sample receiving spot. Inanother embodiment, these particles of color change indicators are addedto the particles of plastic and mixed before sintering to form thesintered porous plastic matrix in the area of the sample receiving spotand also in the sintered porous plastic matrix in the region of the cardoutside of the sample receiving spot in order to indicate that thesample volume has exceeded the sample receiving spot. These particles ofcolor change indicators retain particulate characteristics in thesintered porous plastic matrix as they have a higher melting temperaturethan the plastic particles. When particles of color change indicatorsare employed, the sintering temperature is chosen to sinter plasticparticles but not to melt the dye particles.

Manufacture of Cards

Cards may be made with different methods depending on the composition ofthe card. In one embodiment, when cards are made entirely of sinteredporous plastic, cards are made by placing plastic particles in a mold ofdesired shape and then sintering using heat to form the card. Sinteringtemperatures for specific plastics are known to one of ordinary skill inthe art. The sample receiving spots and non-sample receiving regions onthe card may have the same chemical composition or a different chemicalcomposition. In this embodiment, sample receiving spots are used tocollect, store, transport and/or deliver the samples and non-samplereceiving regions are used to make the card in the desired shapes and toprovide a surface for labeling the card. Based on the design, cards mayhave variety of shapes and arrangements.

In one embodiment, plastic cards are molded. The molding and sinteringconditions to make sintered porous cards depends on the polymer. One ofordinary skill in the art is familiar with the temperatures andpressures that are appropriate for specific polymers.

A representative method of making a single component card follows.Plastic particles, in some embodiments, are sintered at a temperatureranging from about 200° F. to about 700° F. In other embodiments,plastic particles are sintered at a temperature ranging from about 300°F. to about 500° F. The sintering temperature, according to embodimentsof the present invention, is dependent upon and selected according tothe identity of the plastic particles as known to one of ordinary skillin the art.

Plastic particles, in some embodiments, are sintered for a time periodranging from about 30 seconds to about 30 minutes. In other embodiments,plastic particles are sintered for a time period ranging from about 1minute to about 15 minutes or from about 5 minutes to about 10 minutes.In some embodiments, the sintering process comprises heating, soaking,and/or cooking cycles. Moreover, in some embodiments, sintering ofplastic particles is performed under ambient pressure (1 atm). In otherembodiments sintering of plastic particles is performed under pressuresgreater than ambient pressure.

A representative method of making a dual component card with differentsample receiving spots and non-sample receiving regions follows. Thefirst plastic particle mix is deposited in a sample receiving spotportion of a mold. The second plastic mix is deposited in the non-samplereceiving portion of the mold adjacent to the first portion of the mold.Next the first plastic particle mix and second plastic particle mix aresintered to form the cards containing a sampling region and non samplingregion with different properties.

First plastic particles and second plastic particles, in someembodiments, have average sizes ranging from about 1 μm to about 1 mm.In another embodiment, first plastic particles and second plasticparticles have average sizes ranging from about 10 μm to about 900 μm,from about 50 μm to about 500 μm, or from about 100 μm to about 400 μm.In a further embodiment, first plastic particles and second plasticparticles have average sizes ranging from about 200 μm to about 300 μm.In some embodiments, first plastic particles and second plasticparticles have average sizes less than about 1 μm or greater than about1 mm. Sizes of first plastic particles and second plastic particles, insome embodiments, are selected independently.

First plastic particles and second plastic particles, in someembodiments, are sintered at a temperature ranging from about 200° F. toabout 700° F. In some embodiments, first plastic particles and secondplastic particles are sintered at a temperature ranging from about 300°F. to about 500° F. The sintering temperature, according to embodimentsof the present invention, is dependent upon and selected according tothe identity of the first plastic particles and second plastic particlesas known to one of ordinary skill in the art.

First plastic particles and second plastic particles, in someembodiments, are sintered for a time period ranging from about 30seconds to about 30 minutes. In other embodiments, first plasticparticles and second plastic particles are sintered for a time periodranging from about 1 minute to about 15 minutes or from about 5 minutesto about 10 minutes. In some embodiments, the sintering processcomprises heating, soaking, and/or cooking cycles. Moreover, in someembodiments, sintering of first plastic particles and second plasticparticles is conducted under ambient pressure (1 atm). In otherembodiments sintering of first plastic particles and second plasticparticles is conducted under pressures greater than ambient pressure.

A polymeric material, such as a card, produced by sintering firstplastic particles and second plastic particles, in some embodiments ofthe present invention, can comprise a sample receiving spot and anon-sample receiving region, the sample receiving spot comprising thesintered first plastic particles optionally with other additives, andthe non-sample receiving region comprising the sintered second plasticparticles. The shape of the mold can be any desired shape allowing forthe facile and single-step production.

In another embodiment, the sintered porous plastic sample card can besintered into a sheet form on a flat heating moving belt. The heatingtemperature and belt moving speed depend on the polymers as known to oneof ordinary skill in the art. The sintered porous plastic sheet then canbe die cut to the desired size and shape. The sheet can be alsothermally formed into desired shapes.

In one embodiment, cards are manufactured such that the perimeter of thesample receiving spot is somewhat thinner or weaker than the samplereceiving spot or the plastic material outside the perimeter. Thisperimeter may be perforated with thinner, break away regions of plastic.This arrangement facilitates separation of the sample receiving spotfrom the surrounding porous plastic through application of force to thesample receiving spot.

In another embodiment, cards are manufactured such that the perimeter ofthe sample receiving spot is somewhat thicker than the center of thesample receiving spot or the plastic material outside the perimeter.This arrangement facilitates containment of the applied sample to thedesired location. The size and shape of a region of the card are predetermined by the design of the mold.

In yet another embodiment, cards are manufactured such that theperimeter of the sample receiving spot is somewhat thinner or weakerthan the center of the sample receiving spot or the plastic materialoutside the perimeter of the sample receiving spot. This arrangementfacilitates separation of the sample receiving spot from the surroundingporous plastic through application of force to the sample receivingspot. In one embodiment, the perimeter of the sample receiving spot mayappear perforated, with discontinuities in the sintered porous plasticwhere a perforation occurs. These cards also contain a somewhat thickerregion of plastic within the perimeter of the thinner or weaker zone.Such arrangement facilitates containment of the applied sample to thedesired location and also facilitates separation of the sample receivingspot from the surrounding porous plastic through application of force tothe sample receiving spot.

In another embodiment, cards are manufactured such that the samplereceiving spot has a different hydrophobicity from non-sample receivingregions. In a specific embodiment, the sample receiving spot ishydrophilic and the non-sample receiving region is hydrophobic. Theblood sample only wets and wicks into the hydrophilic sample receivingspot. The method of making regions of discrete hydrophobic andhydrophilic porous plastic is described in US Patent Applicationpublication number US2003134100. Cards can be manufactured in the moldor by thermoforming. Thermoforming is a process of forming a profiledproduct from a flat sheet by applying heat and pressure to selectedlocations of flat sheet. In the present invention, in one embodiment,the flat sheet of sintered porous plastic is passed through a heated diewith a profile that generates a desired pattern.

In another embodiment the card comprises sample receiving spotscomprising a sintered porous plastic matrix and regions of non-porousplastic surrounding the sample receiving spots. In one embodiment, thiscard is made using an injection molding process with a hole thataccommodates sintered porous plastic components, such as the samplereceiving spot, channel or sample storage spot. These sintered porousplastic components are inset into the hole in the card. In anotherembodiment in which sample receiving spots are contained in a paper,cardboard, glass or non-porous plastic card, the sample receiving spots,and optionally channels and sample storage spots are made by sinteringplastic to make a sintered porous plastic matrix. The sample receivingspots, and optionally channels and sample storage spots are theninserted into a preformed paper, cardboard, glass or non porous plasticcard containing openings configured to accept the sample receivingspots, and optionally channels and sample storage spots. Such insertionmay be accomplished through a frictional fit. In another embodiment, apreformed paper, cardboard, glass or non porous plastic card containsopenings with flanges configured to accept the sample receiving spots,and optionally channels and sample storage spots.

Operation of the Card.

A liquid sample is applied to the card. In one embodiment, the samplerequires that it is maintained in a wet state and the card is stored ina moist environment for subsequent use or transport, such as mailing. Inanother embodiment, the sample is permitted to dry. In one embodimentthe card may then be stored for subsequent use or transport, such asmailing. Alternatively, after the sample dries, a portion of the cardcontaining the sample may be obtained by cutting the card with a knife,scissors, a sharp punch of desired shape at the cutting surface, oranother tool known to one of ordinary skill in the art. In anotherembodiment, the sample receiving spot may be punched away from the cardby application of force to the sample receiving spot, especially inembodiments wherein the perimeter of the sample receiving spot issomewhat thinner or weaker that the plastic material on either side.When color change indicators are included in the sample receiving spot,the sharp punch of desired shape may be applied to the region of thesample receiving spot that changed color upon application of the liquidsample. At this point, several options exist. The cut portion of thesample receiving spot may be covered and stored until the appropriatetime to perform a test on the sample contained therein. Alternatively,the cut portion of the sample receiving spot may be processed to performa desired test to detect a selected analyte. In one embodiment, the cutportion of the sample receiving spot with a sharp edge may be treatedwith an ionic solution and then placed in a mass spectrometer foraerosolization of analytes on the sample receiving spot. The ionicsolution can be any solution used for electrospray ionization, such as,a solution containing 5 mM ammonium bicarbonate and 100 mM ammoniumacetate, pH=7.8. Other ionic solutions may be used as known to one ofordinary skill in the art. This aerosolization may be achieved through avariety of means such as applying a voltage to the sharp edge of thesample receiving spot fragment. When the sample receiving spot ispolygonal in shape, for example triangular in shape, cutting the samplereceiving spot may not be required as a sharp edge is provided uponpunching the triangular sample receiving spot from the card. Then thecorner of the triangular sample receiving spot may be treated with anionic solution and then placed in a mass spectrometer for aerosolizationof analytes on the sample receiving spot.

Alternatively, the sample receiving spot or a fragment thereof may beadded to a receptacle such as a test tube, centrifuge tube or assaytube, and the sample may be processed, for example, by eluting thesample for assay of an analyte in the sample. The sample receiving spotor a fragment thereof may be cut or punched into a receptacle based onthe card design and requirement. Such receptacles may also containreagents useful in performing an assay of one or more analytes in thesample. Appropriate reagents are known to one of ordinary skill in theart and are chosen based on the analyte to be measured. For example,analyte-specific antibodies, optionally in addition to a colorimetricindicator may be used to bind to a protein and develop a color. In oneembodiment, the sample may contain a protein or a peptide and theelution of the protein or a peptide from the spot or fragment thereofmakes the protein or peptide available for measurement with an enzymelinked immunoabsorbent assay (ELISA) or radioimmunoassay (RIA). Inanother embodiment, the sample may contain another type of biologicalmolecule, such as a lipid, a nucleic acid (for example DNA or RNA), or aneurotransmitter (such as catecholamines, indoleamines, acetylcholine)or metabolites thereof.

The sample card of the present invention can be used in a similar waydescribed by GE Healthcare on their website (http://www.whatman.com) andin their literature concerning the cellulose-based GE DMPK FTA card. Thesample card of the present invention has similar applications and can beused in similar ways as described in following US patents or patentapplications: U.S. Pat. No. 6,627,226, US 2001/0000149, US 2007/0259445,U.S. Pat. No. 5,496,542, U.S. Pat. No. 5,756,126, U.S. Pat. No.5,807,527, U.S. Pat. No. 5,985,327, U.S. Pat. No. 6,168,922, U.S. Pat.No. 6,447,804, U.S. Pat. No. 6,746,841, and U.S. Pat. No. 6,958,392.

Housing

The card may be used without a housing. The card has good mechanicalstrength, rigidity and can be used alone. Print can be applied to thecard to indicate the company logo, to label the sample receiving spots,to label the type of card or other desired labels. A barcode and quickresponse (QR) code can be also directly printed onto the card. The cardmay also comprise a magnetic strip for information storage.

The card can be laminated to the other materials, such as cardboard or aplastic sheet using techniques familiar to one of ordinary skill in theart. The card can also be inserted into a frame sheet using techniquesfamiliar to one of ordinary skill in the art.

The card may be placed in the appropriate storage conditions until theoperator decides to perform the sample analysis. Cards may optionallycontain a storage stabilizing agent, such as a desiccant or an oxygenscavenger. Cards may optionally be stored with a storage stabilizingagent, such as a desiccant or an oxygen scavenger.

Types of Samples

Liquid samples include but are not limited to biological andnon-biological fluids. Biological fluids include, but are not limitedto, bodily fluids such as blood, plasma, urine, peritoneal fluid,pulmonary fluid, pericardial fluid, tears, saliva, cerebrospinal fluid,lymphatic fluids, gastrointestinal fluids, feces, fluids of thereproductive system, and amniotic fluid. Other biological fluids includebut are not limited to culture medium such as cell or tissue culturemedium. Non-biological fluids include water samples including freshwater, sea water, and wastewater samples, organic solution samples,inorganic solution samples, samples from the petrochemical industry suchas samples from oil fields, environmental samples and food samples.Biological and non-biological fluids may contain cells.

In one embodiment, when the biological sample is blood, the samplereceiving spot may contain preservatives, chelating agents or chemicalsuseful in lysing cells and/or denaturing proteins, including enzymes.Samples also include but are not limited to tissues, animal or plantcells, microorganisms (for example, bacteria, viruses, mold, and fungi),and plasmids. Cells include, but are not limited to, cultured cells,epithelial cells, mesothelial cells, endothelial cells and stem cells orother progenitor cells. Cells may be obtained from tissues, organs andbiological fluids using techniques known to one of ordinary skill in theart.

Target analytes include any desired analyte, such as nucleic acid (DNA,RNA), carbohydrates, lipids, proteins, peptides, hormones, antibodies,metabolites, neurotransmitters, immunomodulators, drugs, drugmetabolites, alcohol, ions, or electrolytes.

The following examples will serve to further illustrate the presentinvention without, at the same time, however, constituting anylimitation thereof. On the contrary, it is to be clearly understood thatresort may be had to various embodiments, modifications and equivalentsthereof which, after reading the description herein, may suggestthemselves to those skilled in the art without departing from the spiritof the invention.

Example 1 Porous Plastic Card for Use in Delivery of Small Volume BloodSamples to an Assay

A 100 gm young rat is injected with a drug and blood is sampled overtime to examine the concentration of the drug and its metabolites inorder to establish a pharmacokinetic and metabolic profile.

The rat is anesthetized and its tail vein is used to obtain a 10 μlsample of blood with a capillary tube. The 10 μl sample is applied to asample receiving spot on a porous plastic card and dries. This samplingprocess continues every 30 min for 4 hours and each 10 μl sample isapplied to a different sample receiving spot. The card containing the 10μl blood samples is stored until a time selected for analysis.

Next, a sample of each blood spot is obtained using a punch with acircular shape. The punched circular region of the card containing thesample is then introduced into a centrifuge vial. A methanol solution isintroduced into the vial to extract the drug metabolites. The clearsolution is injected into a LC-MS in order to separate, detect andanalyze the drug and its metabolites and establish a pharmacokinetic andmetabolic profile.

Example 2 Porous Plastic Card for Use in Delivery of Small Volume BloodSamples to a Mass Spectrometer

A 100 gm young rat is injected with a drug and blood is sampled overtime to examine the concentration of the drug and its metabolites inorder to establish a pharmacokinetic and metabolic profile.

The rat is anesthetized and its tail vein is used to obtain a 10 μlsample of blood with a capillary tube. The 10 μl sample is applied to asample receiving spot on a porous plastic card and dries. This samplingprocess continues every 30 min for 4 hours and each 10 μl sample isapplied to a different sample receiving spot. The card containing the 10μl blood samples is stored until a time selected for analysis.

Next, a sample of each blood spot is obtained using a punch with atriangular shape. The punched triangular region of the card containingthe sample is then introduced into the mass spectrometer in order todetect and analyze the drug and its metabolites and establish apharmacokinetic and metabolic profile.

Example 3 Porous Plastic Card for Use in Forensic Pathology

A crime scene investigator arrives at a crime scene involving multipleblood spatters. The investigator uses a pipette to apply 5 μl samples ofblood to individual sample receiving spots on a porous plastic card.Ultraviolet analysis of the crime scene reveals several samples ofreproductive fluids which are collected and applied to sample receivingspots on another porous plastic card. The cards are stored until thelaboratory is available for DNA analysis. A sample is eluted from eachspot and the polymerase chain reaction is used for genomic analysis ofDNA contained in white blood cells and in the reproductive fluids. Theresults are used to identify the crime victim and the perpetrator.

Example 4 Multi-Channel Hydrophilic/Hydrophobic Porous Plastic Card forUse in Delivery of Small Volume Blood Samples to an Assay

A 100 gm young rat is injected with a drug and blood is sampled overtime to examine the concentration of the drug and its metabolites inorder to establish a pharmacokinetic and metabolic profile.

The rat is anesthetized and its tail vein is used to obtain a 100 μlsample of blood with a capillary tube. The 100 μl sample is applied tothe sample receiving spot on a multi-channel hydrophilic-hydrophobicporous plastic card (FIG. 5). The blood wicks through the hydrophilicchannels and reaches the sample storage spots. The card is dried. Thecard containing the 100 μl blood sample is stored until a time selectedfor analysis.

Next, a sample of blood from each sample storage spot is obtained usinga punch with a circular shape. The punched circular region of the cardcontaining the sample is then introduced into a centrifuge vial.Different storage spots may be punched into different vials fordifferent assays or using different protocols. Some storage spots may beretained for future assays.

Example 5 Sintered Porous Dry Blood Card

Powdered polyethylene having an average particle size of about 150 μmwas disposed in a metal sheet (8″×11″× 1/16″) mold, heated to 350° F.for about three minutes and subsequently cooled to room temperature inabout five minutes. The sintered porous polyethylene sheet had anaverage pore size of about 30 μm and pore volume of about 40%.

Example 6 Sintered Porous Dry Blood Card

Powdered UHMWPE polyethylene having an average particle size of about 30μm was disposed in a metal sheet (8″×11″× 1/16″) mold, heated to 350° F.for about three minutes and subsequently cooled to room temperature inabout five minutes. The sintered porous UHMWPE sheet had an average poresize of about 10 μm and pore volume of about 40%.

Example 7 Sintered Porous Dry Blood Card

Powdered high density polyethylene (HDPE) having an average particlesize of about 300 μm was disposed in a metal sheet (8″×11″× 1/16″) mold,heated to 350° F. for about three minutes and subsequently cooled toroom temperature in about five minutes. The sintered porous HDPE sheethad an average pore size of about 80 μm and pore volume of about 40%.

Example 8 Sintered Porous Dry Blood Card

Powdered polystyrene having an average particle size of about 180 μm wasdisposed in a metal sheet (8″×11″× 1/16″) mold, heated to 370° F. forabout three minutes and subsequently cooled to room temperature in aboutfive minutes. The sintered porous polyethylene sheet had an average poresize of about 45 μm and pore volume of about 40%.

Example 9 Hydrophilic Sintered Porous Dry Blood Card

Sintered porous dry blood cards from examples 5-8 were treated with lowpressure plasma. The sample cards were treated with oxygen plasma at 100mtorr and 100 watts (W) for 10 minutes in a plasma machine (Europlasma,Oudenaards, Belgium). The cards became hydrophilic and adsorbed 20 μldeionized water in less than 3 seconds when 20 μl deionized water wasplaced on top of the cards with a pipette.

Example 10 Hydrophilic Sintered Porous Dry Blood Card

Sintered porous dry blood cards from examples 5-8 were treated withsurfactants. The sample cards were immersed in a solution comprises of79% deionized water, 20% isopropyl alcohol and 1% Tween® 20 at roomtemperature for 12 hours and dried at 70° F. for 8 hours in an oven. Thecards became hydrophilic and adsorbed 20 μl deionized water in less than3 seconds when 20 μl deionized water was placed on top of the cards witha pipette.

Example 11 Sintered Hydrophilic Porous Dry Blood Card Comprising DryAnionic Surfactant

A powdered mixture comprising 99.5% of polyethylene powders having anaverage particle size of about 150 μm and 0.5% of sodium dodecyl sulfate(SDS) was disposed in a metal sheet (8″×11″× 1/16″) mold, heated to 350°F. for about three minutes and subsequently cooled to room temperaturein about five minutes. The resulting sintered porous polyethylene sheethad an average pore size of about 30 μm and pore volume of about 40%.The cards were hydrophilic and adsorbed 20 μl deionized water in lessthan 3 seconds when 20 μl deionized water was placed on top of the cardswith a pipette.

Example 12 Sintered Hydrophilic Porous Dry Blood Card Comprising DryAnionic Surfactant

A powdered mixture comprising 99.5% of UHMWPE polyethylene having anaverage particle size of about 30 μm and 0.5% of sodium dodecyl sulfate(SDS) powder is disposed in a metal sheet (8″×11″× 1/16″) mold and isheated to 350° F. for about three minutes and subsequently is cooled toroom temperature in about five minutes. The resulting sintered porousUHMWPE sheet has an average pore size of about 10 μm and pore volume ofabout 40%. The cards are hydrophilic and adsorb 20 μl deionized water inless than 3 seconds when 20 μl deionized water is placed on top of thecards with a pipette.

Example 13

Sintered hydrophilic porous dry blood card comprising dry cationicsurfactant A powdered mixture comprising 99% of polyethylene powdershaving an average particle size of about 150 μm and 1% ofcetyltrimethylammonium bromide (CTAB) is disposed in a metal sheet(8″×11″× 1/16″) mold, heated to 350° F. for about three minutes andsubsequently cooled to room temperature in about five minutes. Theresulting sintered porous polyethylene sheet has an average pore size ofabout 30 μm and pore volume of about 40%. The cards are hydrophilic andadsorb 20 μl deionized water in less than 3 seconds when 20 μl deionizedwater is placed on top of the cards with a pipette.

Example 14 Sintered Hydrophilic Porous Dry Blood Card Comprising DryCationic Surfactant

A powdered mixture comprising 99% of UHMWPE polyethylene having anaverage particle size of about 30 μm and 1% of cetyltrimethylammoniumbromide (CTAB) is disposed in a metal sheet (8″×11″× 1/16″) mold, heatedto 350° F. for about three minutes and subsequently cooled to roomtemperature in about five minutes. The resulting sintered porouspolyethylene sheet has an average pore size of about 10 μm and porevolume of about 40%. The cards are hydrophilic and adsorb 20 μldeionized water in less than 3 seconds when 20 μl deionized water isplaced on top of the cards with a pipette.

Example 15 Hydrophilic Sintered Porous Dry Blood Card with MultilayerPolyelectrolyte Coating

Sintered porous dry blood cards from example 9 were further treated withan polyelectrolyte solution to improve hydrophilic stability. Thefreshly plasma treated sample cards were immersed in 0.25%polyethylenimine (750 KDa) water-alcohol solution (80% deionized waterand 20% isopropyl alcohol) at room temperature for 10 minutes, dried at50° F. for 10 minutes in an oven, immersed in 0.25% polyacrylic acid(250 KDa) water-alcohol solution (80% deionized water and 20% isopropylalcohol) at room temperature for 10 minutes and dried at 50° F. for 10minutes. The cards were hydrophilic and adsorbed 20 μl deionized waterin less than 3 seconds when 20 μl deionized water was placed on top ofthe cards with a pipette.

Example 16 Hydrophilic Sintered Porous Dry Blood Card withPolyelectrolyte and Surfactant Coating

Sintered porous dry blood cards from example 9 were further treated withpolyelectrolyte solution to improve hydrophilic stability. The freshlyplasma treated sample cards were immersed in 0.25% polyethylenimine (750KDa) water-alcohol solution (80% deionized water and 20% isopropylalcohol) at room temperature for 10 minutes, dried at 50 degree for 10minutes in an oven, immersed in 0.1% Zonyl® FSK water-alcohol solution(80% deionized water and 20% isopropyl alcohol) at room temperature for10 minutes and dried at 50° F. for 10 minutes. The cards werehydrophilic and adsorbed 20 μl deionized water in less than 3 secondswhen 20 μl deionized water was placed on top of the cards with apipette.

Example 17 Hydrophilic Sintered Porous Dry Blood Card with Heparin

Sintered porous dry blood cards from examples 5-8 are treated withsurfactant and heparin. The sample cards are immersed in awater-isopropyl alcohol solution (80:20) comprising 1% Tween® 20 and0.5% heparin sodium salt at room temperature for 12 hours and dried at70° F. for 8 hours in an oven. The cards become hydrophilic and adsorb20 μl deionized water in less than 3 seconds when 20 μl deionized wateris placed on top of the cards with a pipette.

Example 18 Hydrophilic Sintered Porous Dry Blood Card withPolyelectrolyte and Heparin Coating

Sintered porous dry blood cards from example 9 are further treated withpolyelectrolyte solution and heparin solution to improve bloodcompatibility. The freshly plasma treated sample cards are immersed in0.25% polyethylenimine (750 KDa) water-alcohol solution (80% deionizedwater:20% isopropyl alcohol) at room temperature for 10 minutes, driedat 50° F. for 10 minutes in an oven and then immersed in 0.1% heparinsodium salt water solution (80% deionized water:20% isopropyl alcohol)at room temperature for 10 minutes and dried at 50° F. for 10 minutesThe cards are hydrophilic and adsorb 20 μl deionized water in less than3 seconds when 20 μl deionized water is placed on top of the cards witha pipette.

Example 19 Sintered Hydrophilic Porous Dry Blood Card Comprising C-18Silica Gel

A powdered mixture comprising 70% of UHMWPE polyethylene having anaverage particle size of about 30 μm and 30% of C-18 silica gel withaverage particle size of 30 μm is disposed in a metal sheet (8″×11″×1/16″) mold, heated to 350° F. for about three minutes and subsequentlycooled to room temperature in about five minutes. The sintered porouscomposite sheet has an average pore size of about 10 μm and pore volumeof about 40%. The cards are optionally further treated with surfactantsolution to provide hydrophilicity.

Example 20 Sintered Hydrophilic Porous Dry Blood Card Comprising IonExchange Resins

A powdered mixture comprising 70% of UHMWPE polyethylene having anaverage particle size of about 30 μm and 30% of Dowex® 50WX2 fine meshresin (200 to 400 meshes) with average particle size of 50 μm isdisposed in a metal sheet (8″×11″× 1/16″) mold, heated to 350° F. forabout three minutes and subsequently cooled to room temperature in aboutfive minutes. The sintered porous composite sheet has an average poresize of about 12 μm and pore volume of about 40%. The cards areoptionally further treated with surfactant solution to providehydrophilicity.

Example 21 Sintered Hydrophilic Porous Dry Blood Card ComprisingChelating Agents

A powdered mixture comprising 95% of UHMWPE polyethylene having anaverage particle size of about 30 μm and 5% ofethylenediaminetetraacetic acid (EDTA) powder with average particle sizeof 50 μm is disposed in a metal sheet (8″×11″× 1/16″) mold, heated to350° F. for about three minutes and subsequently cooled to roomtemperature in about five minutes. The sintered porous composite sheethas an average pore size of about 10 μm and pore volume of about 40%.The cards are optionally further treated with surfactant solution toprovide hydrophilicity.

Example 22 Sintered Hydrophilic Porous Dry Blood Card Comprising DNAStabilizing Agents

A powdered mixture comprising 98% of UHMWPE polyethylene having anaverage particle size of about 30 μm and 2% of uric acid powder withaverage particle size of 50 μm is disposed in a metal sheet (8″×11″×1/16″) mold, heated to 350° F. for about three minutes and subsequentlycooled to room temperature in about five minutes. The sintered porouscomposite sheet has an average pore size of about 10 μm and pore volumeof about 40%. The cards are optionally further treated with surfactantsolution to provide hydrophilicity.

Example 23 Sintered Hydrophilic Porous Dry Blood Card ComprisingChaotropic Agents

A powdered mixture comprising 98% of UHMWPE polyethylene having anaverage particle size of about 30 μm and 2% of guanidinium chloridepowder with average particle size of 50 μm is disposed in a metal sheet(8″×11″× 1/16″) mold, heated to 350° F. for about three minutes andsubsequently cooled to room temperature in about five minutes. Thesintered porous composite sheet has an average pore size of about 10 μmand pore volume of about 40%. The cards are optionally further treatedwith surfactant solution to provide hydrophilicity.

Example 24 Sintered Hydrophilic Porous Dry Blood Card ComprisingMultiple Additives for Blood Preservation

A powdered mixture comprising 90% of UHMWPE polyethylene having anaverage particle size of about 30 μm and 2% of uric acid powder withaverage particle size of 50 μm, 2% of guanidinium chloride powder withaverage particle size of 50 μm, 5% of ethylenediaminetetraacetic acid(EDTA) powder with average particle size of 50 μm and 1% of sodiumdodecyl sulfate (SDS) powder is disposed in a metal sheet (8″×11″×1/16″) mold, heated to 350° F. for about three minutes and subsequentlycooled to room temperature in about five minutes. The sintered porouscomposite sheet has an average pore size of about 12 μm and pore volumeof about 40%. The cards are hydrophilic and adsorb 20 μl deionized waterin less than 3 seconds when 20 μl deionized water is placed on top ofthe cards with a pipette.

Example 25 Recovery of Caffeine from Sintered Hydrophilic Porous Cards

Three hydrophilic sintered polyethylene sheets were selected for testsampling properties. The sheets had different pore sizes (100 μm, 50 μm,and 8 μm) with thicknesses of 1.6 mm, 1.6 mm and 0.25 mm, respectively,as shown in Tables 1 and 2. The 100 μm sheet comprised 0.2% of theanionic surfactant sodium N-methyl-N-oleoyltaurate. The 50 μm sheetcomprised 0.2% of the anionic surfactant sodiumN-methyl-N-oleoyltaurate. The percentage of the surfactant is theblended weight percentage before sintering. The 8 μm sheet was treatedwith plasma activation and sequentially treated with an aqueous solutionof 0.25% polyethylenimine an aqueous solution of 0.25% poly(acrylicacid).

Artificial plasma was formulated with phosphate buffer, red food dye,bovine serum albumin and sodium azide. Caffeine was obtained from SigmaAldrich. Caffeine was mixed with artificial plasma to form a 10 mg/mlsolution. A caffeine standard solution (10 mg caffeine/ml) was made andserially diluted in deionized water solution. The standard UV absorptioncurve for these serially diluted caffeine solutions is show in FIG. 8.The UV absorption was measured on a Thermo-Fisher NanoDrop 2000 machine.The caffeine was measured at the wavelength of 273 nm. The wavelengthselection was based on the caffeine UV absorption curve and the UVabsorption curve for artificial plasma.

20 μl of artificial plasma was pipetted onto each hydrophilic sheet. Thedifferent sheets had clearly visible differences in sample spotdiameters as indicated in Table 1. Properties of the sheet samples arelist in Table 1. These samples were used as a background measurement inorder to measure caffeine samples.

TABLE 1 Artificial plasma spot on the card samples. Porex Sheets Samplesize (μl) Spot diameter (mm) Thickness (mm) 100 μm 20 6 1.6  50 μm 20 81.6  8 μm 20 18 0.25

20 μl of artificial plasma containing 10 mg/ml caffeine (total of 200 μgcaffeine) was pipetted onto separate sheet samples with the sameproperties. The samples were dried at room temperature for 2 hours. Thensample spots were punched with a 6 mm diameter paper punch. Theresulting 6 mm diameter disks were separately transferred into 7 mlglass vials. The samples in the vials were extracted with 1 ml deionizedwater for 2 hours. The UV absorption of these aqueous extracts weremeasured for the samples with artificial plasma and the samples withcaffeine in the artificial plasma. The difference for the same samplewith and without caffeine was measured for caffeine released from thesampling cards. The readings were estimated to the closest 5 μg/ml usingthe caffeine deionized water standard curve. The results in Table 2 showcaffeine recoveries of 65% to 87.5%.

TABLE 2 Caffeine recovery from Porex sheets. Measured Caffeine UVAbsorption Factor Concentration Recovery Porex Sheets (273 nm) (punchsize) (μg) % 100 μm 0.77 1 175 87.5  50 μm 0.35 1.78 150 75  8 μm 0.0659 130 65

All patents, publications and abstracts cited above are incorporatedherein by reference in their entirety. It should be understood that theforegoing relates only to preferred embodiments of the present inventionand that numerous modifications or alterations may be made thereinwithout departing from the spirit and the scope of the present inventionas defined in the following claims.

1. A card for receiving a liquid sample comprising: a card comprising asintered porous plastic matrix comprising at least one liquid samplereceiving spot; and a region surrounding the at least one liquid samplereceiving spot.
 2. The card of claim 1, wherein the plastic is selectedfrom the group consisting of polyethylene, polypropylene, polyvinylidenefluoride, polyamide, polyacrylate, polyacrylic nitrile, ethylene-vinylacetate, polyester, polycarbonate, polystyrene, andpolytetrafluoroethylene or a blend thereof.
 3. The card of claim 2,wherein the polyethylene is selected from the group consisting of highdensity polyethylene, low density polyethylene and ultra high molecularweight polyethylene, or a blend thereof.
 4. The card of claim 1, whereinthe at least one liquid sample receiving spot and the region surroundingthe at least one liquid sample receiving spot are independentlyhydrophilic or hydrophobic.
 5. The card of claim 1, wherein the at leastone liquid sample receiving spot comprises a perimeter which is weakerthan the area of the at least one liquid sample receiving spot withinthe perimeter.
 6. The card of claim 1, wherein the at least one liquidample sample receiving spot is suitable for introduction into a massspectrometer.
 7. The card of claim 1, further comprising a functionaladditive.
 8. The functional additive of claim 7, wherein the functionaladditive is a color change indicator, a surfactant, a chelating agent,an anti-clotting agent, a polyelectrolyte, an enzyme inhibitor, a celllysing reagent, an antioxidant, a DNA stabilizing agent, or a chaotropicagent or a combination thereof.
 9. The card of claim 1, wherein theregion surrounding the at least one liquid sample receiving spotcomprises porous plastic, non-porous plastic, glass, paper or cardboard.10. The sintered porous matrix of claim 1, having a porosity of fromabout 20% to about 80%, from about 25% to about 70%, from about 30% toabout 60%, or from about 30% to about 50%.
 11. The sintered porousmatrix of claim 1, having a pore size of from about 1 μm to about 200μm, from about 10 μm to about 100 μm, or from about 20 μm to about 60μm.
 12. The sample receiving spot of claim 1, having a thickness of fromabout 100 μm to about 5 mm, from about 200 μm to about 3 mm, or fromabout 0.5 mm to about 2 mm.
 13. The card of claim 1, further comprisinga channel connecting the least one liquid sample receiving spot to atleast one sample storage spot.
 14. The card of claim 1, wherein theregion surrounding the liquid sample receiving spot has a region toaccept labeling, writing, a barcode, a QR code, a magnetic strip, or acombination thereof. 15.-17. (canceled)
 18. A method for liquid samplecollection, storage, transport, and/or delivery to an analytical devicecomprising: providing a card comprising a sintered porous plastic matrixcomprising at least one liquid sample receiving spot and a regionsurrounding the at least one liquid sample receiving spot; applying aliquid sample to the at least one liquid sample receiving spot; removingat least a portion of the at least one liquid sample receiving spot fromthe card; and, storing the removed portion of the liquid samplereceiving spot, transporting the removed portion of the liquid receivingspot or delivering the removed portion of the liquid sample receivingspot to an analytical device.
 19. The method of claim 18 comprisingpermitting the liquid sample to dry after applying the liquid sample tothe at least one liquid sample receiving spot.
 20. The method of claim18, wherein the liquid sample is a biological fluid or a non-biologicalfluid.
 21. The method of claim 20, wherein the biological fluidcomprises blood, plasma, urine, peritoneal fluid, pulmonary fluid,pericardial fluid, tears, saliva, cerebrospinal fluid, lymphatic fluid,gastrointestinal fluid, feces, a fluid of the reproductive system,amniotic fluid, culture medium, cells, microorganisms or plasmids. 22.The method of claim 18, further comprising treating the removed portionof the at least one liquid sample receiving spot with an ionic solution.23. The method of claim 18, further comprising eluting the sample fromthe removed portion of the at least one liquid sample receiving spot.